When a giraffe sleeps, where does it put its 2-meter-long neck?

Have you ever wondered what a sleeping giraffe looks like and where their necks rest when they sleep?

Nap time: about the same as waking time

Humans once thought that giraffes were animals that never sleep. This misconception is because giraffes not only sleep in short, fragmented periods of time, but also their napping postures look little different from when they are awake .

If a giraffe lies down and lets its long, heavy neck fall completely, it will be difficult for it to get up immediately from its resting state, which greatly increases the risk of being preyed on. Therefore, in order to reduce the risk, adult giraffes must control their sleep duration and not let their bodies completely relax most of the time .

Observations of zoo giraffes show that these animals sleep a total of about 4.6 hours per day. Most of the sleep is short naps in standing or lying positions, and the giraffes keep their necks vertically upward when they sleep . However, after falling asleep, the angle of the giraffe's neck is usually lower than when awake, and sometimes the angle with the ground can even drop to 30 degrees - it feels like our heads gradually lowering when we doze off in class.

When taking a nap, a giraffe's neck may be angled lower | Tuchong Creative

Deep Sleep: Transformed into a Swan

When sleeping lying down, giraffes also have very short periods of deep sleep . Only at this time will their necks relax - the giraffe will suddenly bend its neck backwards and rest it on its buttocks or hind legs, sleeping like a swan . The giraffe's relatives, the okapi, as well as antelopes and cattle, also adopt similar postures when sleeping.

The standard posture of a giraffe in deep sleep | Naoko Takagi et al.

This swan sleeping position is very rare, partly because deep sleep usually occurs at night, and partly because each deep sleep lasts very short. Observations with infrared cameras show that each "swan sleeping position" of giraffes usually does not last more than 3 minutes , and the sleep time of resting the neck only accounts for 4.7% of the total sleep time.

The "swan sleeping position" is very short, usually not lasting more than 3 minutes each time | thomsonsafaris.com

Scientists speculate that these brief periods of neck relaxation may correspond to rapid eye movement sleep , a stage of sleep when the brain is particularly active and dreams occur frequently. However, no experiments have actually proved that giraffes dream while "transforming into swans" - mainly because it is difficult to perform EEG tests on these big guys.

Little Giraffe: Let Yourself Go

The above are all about adult giraffes, but the sleeping posture of newborn giraffes will be more free.

Giraffe babies need much more sleep than adult giraffes. In the first two days after birth, baby giraffes spend 25% of their time sleeping , and 90% of their sleep is deep sleep with their necks relaxed . As they age, the time they spend lying down to rest becomes shorter and shorter.

Baby giraffe falling asleep | Virry

The deep sleeping postures of baby giraffes are more varied. Having just come into this world, they seem to have not yet mastered the correct way to control their necks .

For example, the baby giraffe Anzi at the Tobe Zoo in Ehime Prefecture, Japan, lies her neck flat when she sleeps, with her entire body pressed against the ground :

I lie down｜Ehime Prefectural Zoo【Official】

The baby giraffe born in Kochi Prefecture Zoo in Japan slept in a twisted version of the standard "swan position" :

My Volume｜Masatoshi Kasahara

No matter which posture you take, the cervical spine seems to be under a lot of pressure...

References

[1]https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2869.1996.00010.x

[2]https://onlinelibrary.wiley.com/doi/abs/10.1002/zoo.21511

Author: Window Knocking Rain

Editor: Mai Mai, Wan Wan

Title image source: Kasahara Masatoshi